Jan 19 (Reuters) - U.S. fertilizer company Mosaic Co on Monday estimated that it would post a larger fourth-quarter profit than expected and surpassed its targets for phosphate sales.

Mosaic, the world’s largest producer of finished phosphate products and North America’s second-biggest potash producer, said it expects to earn 93 to 98 cents per share in the quarter including one-time items. Analysts expected, on average, earnings of 58 cents per share, according to Thomson Reuters I/B/E/S.

Excluding items, earnings for the quarter are expected at around 83 to 88 cents per share, Mosaic said.

Demand for potash and phosphates exceeded the company’s expectations in the period, Mosaic Chief Executive Jim Prokopanko said in a statement. Retail fertilizer buyers came to market in force to place inventory in position for what they expect to be a strong spring fertilizer application season for farmers, Prokopanko said.

He said he expects strong demand for both crop nutrients to extend into 2015.

The company sold 3.3 million tonnes of phosphate products during the quarter, exceeding its previous guidance of 2.5 million to 2.8 million tonnes, but just shy of the year-ago quarter’s 3.4 million.

Mosaic said potash volumes looked to fall at the high end of its guidance range of 2.0 million to 2.3 million tonnes during the fourth quarter, compared to 1.9 million last year.

The company also said potash and phosphate margins would exceed earlier guidance. (Reporting by Rod Nickel in Winnipeg, Manitoba; editing by G Crosse and Cynthia Osterman)